Arab Poultry Breeders Co. The Role of Vaccination & Lab Monitoring in The Control of Poultry Diseases. DR. EMAD SHAKER Arab Poultry Breeders Co. Saudi Arabia

Vaccination & Lab Monitoring Cleaning / Disinfection Vaccination Feed All-in All-out Management Hygiene Control of Rodents & Insects Flock management

Health is a balance Disease agents: Resistance: intestinal flora Deficiencies Toxins Viruses bacteria Parasites Resistance: Good feed intestinal flora Immunity * Local * Systemic

Defense System of Chickens against Infections Specific Immune System

Defense System of Chickens against Infections Specific Immune System Peripheral lymphoid tissue Harderian gland Caecal tonsilles Spleen GALT Primary Organs Thymus gland T-cell system  cell-mediated immunity Bursa of Fabricius B-cell system  humoral immunity Bone marrow Precursor blood cells Yolk sac Maternal immunity

Basics of Vaccination in Poultry Elements of a Vaccination Program Number of Vaccinations Type of Vaccines Age of the First Vaccination GOOD VACCINATION PROGRAM DESIGN Interval between Subsequent Vaccinations Route of Vaccination 1. Stimulation & Maintenance of Protective Immunity 2. Development of Immunologic Memmory

Basics of Vaccination in Poultry Requirements for Good Immune Response Correct Vaccine Correct Vaccine Storage Good Nutrition GOOD IMMUNE RESPONSE No Immune Suppression Good Administration Technique No Stress Correct Vaccination Programme Healthy Birds

Administration of a sub-optimal dose of vaccine. Basics of Vaccination in Poultry Possible Reasons of Vaccination Failures Administration of a sub-optimal dose of vaccine. Poor vaccine quality (rare). Improper handling of the vaccine during transport and storage. Errors in the vaccination technique. Immune suppression. Immune suppressive viral infections. Stress. Mycotoxines. High levels of maternal antibodies. Strong field challenge.

Basics of Vaccination in Poultry Possible Reasons of Vaccination Failures The causative agent is not covered by the used vaccine (e.g. IBV variants, AIV subtypes, E. coli serotypes). Vaccination is too late. Birds are already infected at time of vaccination. Field infection occurs before development of vaccinal immunity. Weaning of vaccinal immunity after time.

Basics of Vaccination in Poultry Live Vaccines Advantages Create complex immunity Humoral + cell-mediated. Different classes of antibodies. Rapid onset of vaccinal protection. Easy mass application. No adjuvans needed. No hypersensitivity reactions. Production in big quantities. Disadvantages Vaccine agent is present in poultry population. Possibility of shedding of the vaccine agent. Post vaccinal reactions are possible.

Basics of Vaccination in Poultry Inactivated Vaccines Advantages No introduction of a “new living agent”. No shedding of the vaccine agent. No post vaccinal reactions. Accurate individual vaccination. Disadvantages Reactions of hypersensitivity possible. Slow onset of protection. Humoral immunity only. High labour costs for application. Expensive production of high quality vaccines.

Basics of Vaccination in Poultry Methods of Vaccine-Application Individual Applications: Eye drop vaccination Very efficient. Highly labour intensive; use only specific diluent. Wing web, i.m. & s.c. injection Highly labour intensive; use only sterile equipment and specific diluent for live vaccines.

Basics of Vaccination in Poultry Methods of Vaccine-Application Mass-Applications: Drinking water vaccination Rapid, easy, very economical, safe. No disinfectants; control water quality; control water system and drinker. Spray vaccination Rapid, good immune response. Post vaccinal reactions possible (esp. in Mg+); use distilled water only; large drops for young chicken and small drops for old chicken; control correct function of equipment.

Lab Monitoring

Main Tasks For Veterinary Labs (Poultry Dept.): Organized disease control program. Early Warning System (EWS). Corrective Action can be taken before disease / production losses. - Measuring of Vaccination Performance. (Performing Q C on Vaccine quality, Vaccine application &Vaccination method). Diagnostic Services. Research on infections.

Example for Organized Monitoring Program Breeders / Layers Age Sample Test Day 1 Transfer box paper Serum Salmonella. MG – IBD – SE-SP/G - AI Week 9 Cloaca swabs Salmonella ND – IBV - etc Week 16 Droppings Se/St- MG –ND – AI -etc Week 22 SP/G-ND – AI – MG -etc Week 45 Week 62 Se/St- MG –ND- AI -etc

Example for Organized Monitoring Program Broilers Age Sample Test Day 1 Transfer box paper Serum Salmonella. MG – IBD - AI - 10 days before exit Droppings Salmonella - Marketing Age ND – IBV – AI - IBD

Example for Organized Monitoring Program Slaughter house Time Sample Test Entrance Caecal Content Salmonella. Campylobacter Exit Neck Skin Salmonella

Serological Monitoring Most Important serological tests 1- Hemagglutination Inhibition test (HI). 2- ELISA (indirect). 3- Rapid plate agglutination test (RPA). 4- Agar gel precipitation test (AGPT).

1- Must know what result to expect prior to testing When Conducting Serological monitoring has to know 2 basically things:- 1- Must know what result to expect prior to testing (Set Standards for Successful Vaccination) 2- Must know what action to take if results are not according expectation.

Interpretation of vaccination results by ELISA is usually done by evaluating the 3 main key components of immune response after vaccination, which are:-

1- Intensity of Response:- As indicated by the Mean Titer. Do the birds develop sufficient titers levels that are in the expected range for the vaccine used? These expected titers following vaccination are often called “ Baseline Titers” these Baseline titer values may vary according to type of bird , age , vaccine type , vaccination program, and other factors. Therefore, one should make their own baselines for there own vaccination programs and local conditions.

% CV Uniformity 2- Uniformity of Response:- As indicated by the % CV. Is the vaccine actually getting to the all birds or not. The general guidelines for % CV following vaccination are as follows:- % CV Uniformity Less than 30 % Excellent From 30-50 % Good Greater than 50 % Need to Improve

Persistency of Response:- As indicated by Mean Titer response over Time Do titers persist long enough over time, or is another vaccination needed to boost titers above minimum protective levels.

Suspect Titer Infection Examples of Vaccination Baselines Titers in Broiler:- Test Vaccine Type Mean titer range at 35 - 40 D Suspect Titer Infection NDV -Live, 2x D.W 2000 – 5000 More than 7000 -Live, 2x Spray 4000 – 8000 More than 10000 IBV -Live, 1x (H120) 800 – 1500 More than 3000 -Live, 2x (H120) 2000 – 4000 More than 6000 IBD -Live, 1x (intmed.) 2500 – 4500 -Live, 2x (intmed.) 3000 – 6500 More than 9000

Examples of Vaccination Baselines Titers in layers or Breeders:- Test Vaccine Type Mean titer range Wks after Vac. To test NDV -Live (Lasota) 2000 – 8000 2 – 3 wks -Inact. 10000 – 15000 4 – 7 wks IBV -Live (H120) 2000 – 4000 3 – 5 wks 6000 – 17000 5 – 7 wks IBD -Live (intmed.) 2500 – 7000 3 –5 wks 7000 – 12000

Microbiological Monitoring of Hatchery Hatcheries need a continuous program to monitor the microbial populations in the hatchery. Monitoring the hatchery at least every 6 -8 weeks.

Microbiological Monitoring of Hatchery Take samples from every area in the hatchery and equipments. Some of more important area to be monitored include: Air intake & outlets, Setters, Hatchers, Air in chick holding and egg storage room, Tray wash area, water, and vaccination equipment.

Microbiological Monitoring of Hatchery Samples Required: Swab method for counting - Air Samples. - Egg shell monitoring by rolling method. - Fluff samples (Bacterial count – Salmonella ) - Stamping with plate count agar (Rodac method) - Sterility testing for vaccine equipments. Chicks ( cull Chicks for Salmonella testing)

Microbiological Monitoring of Hatchery - Interpretation: - Swab counting method. - Swab from a tow inch square area: - Less than 10 colonie Good. - 10 –30 colonie Moderate. - Above 30 colonie Heavy Contamination

Microbiological Monitoring of Hatchery - Interpretation: - Air Samples Count (Salder, 1975). Bacterial Colony Count Score Setters Rooms 0 – 10 0 - 15 1- Excellent 11 – 25 16 - 36 2- Good 26 - 46 37 – 57 3- Average 47 – 66 58 – 76 4- Poor 67 or more 77 or more 5- Bad

Microbiological Monitoring of Hatchery Interpretation: - Fluff samples (Microbial counts /gram). (Magwood . - 1962) Bacterial Colony Count Score -25,000 Excellent - 50,000 Good - 100,000 Fair 100,000 + Poor

Bacterial Colony Count Microbiological Monitoring of Hatchery Interpretation: - Stamping with plate count agar (Rodac method) . (Stinson and Tiwari, 1978). Bacterial Colony Count Score 0 – 5 Excellent 6 – 15 Good 16 – 30 Fair 31 – 50 Poor 50 + Unacceptable

Conclusion Vaccination & Laboratory Monitoring a very effective tools to control infectious diseases in poultry.

Thanks for your Attention